JPH04154984A - Plating method for hoop material - Google Patents

Abstract

PURPOSE:To improve accuracy of plating position by giving tension to a hoop material on a plating stage to cause elastic deformation so that the pattern of the hoop material coincides with the pattern of a plating tool. CONSTITUTION:A lead frame 1 of hoop material is released with a releasing mechanism 2 and passed through a pretreatment stage 3 and accumulator stage where the length of intermittent feeding. Tension applied on the hoop material 1 to be supplied to the plating stage 6 is controlled with a weight 5 of the accumulator 4. The hoop material 1 is intermittently moved to the following stages with an intermittent feeding mechanism 9, and during the feed is stopped, the hoop material is subjected to spot plating and post treatment 8. If displacement of the hoop material 1 in a state of no tension given occurs on the plating mask which is the most distant from a positioning device 7, weight is added to the weight 5 of the accumulator 4 to apply tension. The additional weight is controlled to correct the displacement by the elastic deformation of the hoop material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for plating a hoop material lead frame.

(Prior Art) The apparatus used in the method for plating hoop material lead frames has a part in which a pre-processing section 3 continuously processes a formed lead frame 1 sent out from a sending mechanism 2, as shown in FIG. 3, for example. , an intermittent processing section consisting of a spot plating section 6, a positioning mechanism 7, a post-processing section 8, an intermittent feeding mechanism 9 that feeds the lead frame at regular intervals, a lead frame washing/drying mechanism 12, and a winding mechanism 11. The whole is made up of the parts that are processed.

Therefore, the positional error required for spot plating is ±
0.05wn is required.

(Problem to be Solved by the Invention) In order to improve the productivity of the hoop material lead frame plating method described above, it is possible to increase the length of the spot plating part and increase the distance of one intermittent feed. It will be done. Since the plating time is the same for the same type of product, the amount of plating that can be plated at one time increases by extending the plating area, which improves productivity. However, since the hoop material has cumulative dimensional errors during press molding,
Plating misalignment occurs in a lead frame plated at a portion remote from the plating positioning mechanism.

For this reason, there is a limit to the length of the intermittent feed of the plating section. The present invention aims to eliminate the plating position shift due to accumulated errors during molding of this material hoop lead frame.

(Means for Solving the Problems) In order to solve the above problems, the present invention utilizes elastic deformation of the hoop lead frame in the plating part by applying tension to the hoop lead frame, and Improve plating position accuracy by matching the hoop material lead frame pattern to the pattern.

(Function) When punching and forming a single roll of hoop material lead frame,
It has been empirically known that a certain degree of dimensional error occurs, and the error is constant per unit length, as shown in FIG.

If this unit length is Ω and the dimensional error per unit length is ΔQ, then in a plating pattern made according to the design dimensions and m times the unit length, if the plating position is aligned at the left end as shown in Figure 2, At the right end, a positional shift to mX8 occurs.

(However, Fig. 2 shows an example where m = 3.) Therefore, as shown in Fig. 1, if a lead frame stretched with a tension T is attached to a plating pattern made in advance by ΔL longer than the design dimensions per unit length, , since the elastic deformation due to tension T is constant per unit length, if the amount of elongation is ΔQ', the dimensional elongation per unit length is as shown in Figure 1.
Δα+ΔQ'. ΔQ' so that this ΔΩ + ΔQ' and the extended length ΔL of the plating pattern are the same.
Adjust.

That is, by adjusting the tension T, it becomes possible to position the plating.

(Example) Examples are shown below.

Since a device having the same mechanism as that shown in FIG. 3 was used, the explanation will be made with reference to FIG. 3.

2 is a feeding mechanism from which the hoop material lead frame is fed into the plating apparatus. The lead frame passes through the preprocessing section 3 and adjusts the length of intermittent feeding at the accumulator section. The weight 5 of this accumulator section adjusts the tension applied to the hoop material lead frame that enters the next plating section. 13 is a plating pattern jig whose length is 1200 nwn (twice the normal length) to improve productivity. 9
is an intermittent feed mechanism. 7 is a positioning mechanism placed immediately after the plating post-processing section 8.

In the above configuration, the hoop material is fed by the intermittent feeding mechanism 9.
The substrate is intermittently fed back in steps of 0wwn, and sub-plating and post-processing are performed while the intermittent feeding is stopped. When a hoop material lead frame is loaded in a device with such a configuration,
When no tension was applied, a positional shift of about 0.1 m occurred on the plating mask furthest from the positioning device 7.

In this state, a weight is added to the weight of the accumulator section, tension is applied, and the amount of weight is adjusted until the misalignment is corrected by its elastic deformation.

After performing this position adjustment, the plating equipment was operated and the plating position deviation of the completed plated lead frame sample was measured. All samples had a position deviation amount of ±0.
It was less than 0.05mm.

(Effects of the Invention) As explained in detail above, according to the hoop material plating method of the present invention, the plating position shift is reduced, and the length of the plating pattern can be more than doubled, which improves productivity. effective.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the positional relationship between the lead frame and the plating pattern when tension T is applied. FIG. 2 is a diagram showing misalignment between the lead frame and the plating pattern in a state where no tension is applied. FIG. 3 is an overall view of a plating apparatus used for carrying out the present invention. 1... Lead frame 2... Feeding mechanism 3.
...Preprocessing section 4.10...Accumulator section 5.
... Weight 6 ... Spot plating section 7 ... Positioning mechanism 8 ... Post-processing section 9 ... Intermittent feeding mechanism 11 ... Winding mechanism 12 ... Washing and drying mechanism
13... Plating pattern jig. -(N (V) Dimension h

Claims (1)

[Claims] A hoop material feeding mechanism, a plating pre-processing section, a plating section, a plating post-processing section, a positioning mechanism, an intermittent feeding mechanism, and a hoop material winding mechanism are arranged in series, and the pre-processing section and the plating section are arranged in series. In a hoop material plating method that uses a plating device that has an accumulator between the intermittent and intermittent feeding mechanism and the winding mechanism, by applying tension to the hoop material and utilizing the elastic deformation of the hoop material. , a hoop material plating method characterized by improving plating position accuracy.